In modern wireless communications systems, use is often made of so called MIMO technology, Multiple Input, Multiple Output. In MIMO technology, use is made of a wireless communications channel, i.e. a radio channel, in order to transmit two or more data streams simultaneously. A user terminal, a UE within a MIMO system, is equipped with a plurality of antennas in order to receive the various MIMO data streams. The number of MIMO streams supported by the radio channel at a given moment is referred to as the MIMO rank of the radio channel.
The MIMO rank of the radio channel varies continuously, and a radio channel with a high rank (i.e. strong signal, low interference and different channel propagation between the transmitter antennas and receiver antennas) will enable the use of more MIMO streams, and conversely, poor radio channel conditions and a low degree of scatter in the radio propagation environment (lower rank) will make it necessary to use fewer MIMO streams; in fact, sometimes only one stream will be supported, i.e. the MIMO rank will be one.
The radio channel conditions which offer a higher or a lower MIMO rank will change as a user moves within the system. Often, even a small move will change the channel conditions so that a different MIMO rank is supported, either in the case of improved channel conditions which will enable a transition to additional MIMO stream(s), or in the case of deteriorating channel conditions which necessitate a transition to a fewer MIMO stream(s).
The very same radio channel conditions which vary with a user's movements within a system and cause transitions to lower or higher MIMO ranks also apply for the case of communication without MIMO technology, i.e. in effect corresponding to a system with a MIMO rank of one.
US Patent Application 2008/0318626 A1 discloses a mobile communication device with a motion sensor for generating motion signals which are sent to a game device.
US Patent Application 2008/0318626 A1 discloses a circuit which comprises an on-chip gyro which generates a motion parameter based on the motion of the circuit, as well as a GPS receiver that generates GPS position data for the circuit. Based on the motion parameter, motion data are produced, and based on the GPS position data together with the motion data, position information is generated.